Conveying and screening apparatus



July 3, 1923.

E.E. LANDAHL CONVEYING AND SCREENING APPARATUS Filed Nov. 22, 1920 2 Sheets-Sheet l gnue'ntoz July 3,1923.

E. E. LANDAHL CONVEYING AND SCREENING APPARATUS 2 Sheets-Sheet 2 Filed Nov. 22, 1920 jwuentoz Wr/vEss I M (1H0: neg

Patented July 3, 1923.

. UNITED STATES Aren't OFFICE.)

EUGENE E. LANDAHL, or OAK PARK, ILLINOIS.

GOTT VEYING'AND SCREENING APPARATUS.

Application filed November 22, 1920. Serial No. 425,881.

Improvements in Conveying and Screening Apparatus; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable othersskilled-in the art to which it appertain s to make and use the same."

This invention relates to conveying and screening apparatus; and while the principles of the invention are applicable broadly to apparatus for conveying and screening articles and materials generally, the invention' relates more particularly to apparatus for conveying and'screening coal.

Coal as it comes from the mine is in lumps of'various sizes mixed with line coal, dust and dirt. The slack or fines which is present in considerable quantity in run of the mine coal is practically worthless except for special purposes and it is therefore necessary to separate this slack from the'lump coal.

It'is also necessary to. separate from the coal fragments of slate and similar materials which have no combustible value, and which are mixed with the good coal as it comes. I from the mine.

While the slack or fines is ordinarily of little or no value, it is of the utmostimportance that after being separatedfrom the good coal :it be'conveyed to some convenient point for collection or disposal instead of allowing it to accumulate wherever it may fall after being separated. It is desirable that the" number of conveyors, chutes, etc.,'used to carry thecoal from the mine to the car be as small as possible to avoid subjecting the coal to consequent breakage and formation-of additional quantities of slack or lines due to this handling.

It is a principal object of the present invention to provide apparatus which will not only completely and thoroughly separate fines from lump s, but which will also convey the separated? fines and lumps simultaneously in the same direction to separate points of discharge? while at thesame time preventing the formation of additional quantities of lines or slack by avoiding rough and unnecessary handling.

Broadly speaking, the lmproved appara his is characterized by a conveying and screening sur'facej made up of an endless series of connected? screen sections adapted to convey the large lumps and allow the fines to drop through the screen sections on to a conveyor-trough below and to be simultaneously conveyed in the same direction w1th the lumps, the lumps and fines-being carried to separate pointsof'discharge. As a means for ensuring complete separation of the lumps from thefines the conveyor-screen is most desirably adapted to carry the coal up an incline and then down another in.- cline in order to allow a certain amount of sliding and gentle agitation of the coal being carried and thus to secure the thorough,

screening desired. The separating effect thus obtained is especially efiective by reason of the novel construction and arrange ment of the elements comprising the endless conveyor-screen, as will hereinafter appear. A subsequent substantlally horizontal run of the conveying and screenlng surface provides a. picking table to allow slate and similar incombustible material to be picked out.

A practical embodiment of the principles. of the'inventio'n will now be described in detall and further advantages of the improved construction will be pointed out.

The particular construction here illustrated serves merely as an explanatory example of apparatus within the scope of the broad invention and it' is to be understood that "various changes in mechanical details and arrangement may be made Without departing Q from the broad invention. illustrated in the accompanying drawings is adapted more particularly for use inconveying and screening -coal.

In the drawings Fig. 1 is adiagrammatic si one practical form of apparatus embodying my Invention; I

The" app aratus de elevation of Fig. 2 is an end view of the same looking from the right in Fig. 1;

,Fig. 3 is a fragmentary top plan viewof the conveyor-screen on an enlarged scale;

Fig. 4' is a fragmentary longitudinal sectiona l view on line H of Fig. 3;

5 is a transverse sectional View taken on line 5''5 of Fig. 4.

Referring to the drawings,'10' indicates generally an endless conveyorhaving a conveylng and screening surface 11 attached to and carried. by two strands 121 and '13 of endless roller chain passed around pairs of; end sprocket wheels 14 and 15. These pairs of sprocket wheels are mountedon'shfafts16- and 17 j'ournaledirrbearings 18and 19 I spectively, supported by a suitable framework (not shown). At least one set of bearings is adjustable so that the tension of the conveyor-screen may be adjusted. means (not shown) are employed for driving at least one pair of the sprocket wheels to advance the screening and conveying surface. The upper run of the conveyor-screen is passed over and supported by a pair of sprocket wheels mounted on shaft 21, said shaft being journaled in adjustable bearings 22 supported by a suitable framework (not shown). The sprocket wheels 20are niounted intermediate and at a higher level than the end pairs 14 and 15, which latter are substantially on the same level, a hump or knuckle being thus formed in the upper run of the conveyor-screen in order to cause a thorough and complete screening of the coal by the conveying and screenin surface. In the particular apparatus illustrated, the intermediate sprocket wheels 20 are so mounted between the end pairs 14 and 15 that the upper run of the conveying and screening surface forms a substantially horizontal run 23, an upwardly-inclined run 24, a downwardly-inclined run and a second substantially horizontal run 26. The run of the mine coal is fed from the coal tipple at the mine, for example, on to the first substantially horizontal run 23 of the screening and conveying surface by chute 27. In landing on the conveying and screening surface, the coal will partly screen itself some of the lines passing through the screen surface; while the lumps, together with some of the unscreened fines, are carried'forward by the advancing conveyor-screen. As the conveyor-screen advances up the incline 2st, a certain amount of sliding b'ack occurs and a resultant gentle agitation of the coal on the conveyor will take place. thus promoting a further screening effect which is largely completed by the subsequent forward sliding and gentle agitation of the coal on the downward incline 25. It is to be noted that on the incline 24 the coal slides in a direction opposite to that of the conveyor-screen travel; while on incline 25 the coal slides in the same direction as the travel of the conveyor-screen. As already explained, by the time the coal has passed over the hump or knuckle the fines are substantially completely separated from the lumps, which latter are then carried along the second sub-- stantially horizontal run 26 of the screening and conveying surface. This section of the conveyor-screen forms a picking table, affording an opportunity for persons stationed on both sides of the apparatus to pick out lumps of slate and other incombustible matter mixed with the salable coal; From the picking table the good lump coal falls into a chute 28 and thence into a railroad car, bin, or the like. The separated fines are Suitable collected and conveyed to a separate point of discharge as will be hereinafter described.

In the desirable practical construction here illustrated, the conveyor-screen 10 comprises a series of pans or aprons 29 connected together to form an endless screening and conveying surface 11 attached to and carried by two strands 12 and 13 of endless roller chain. Each strand of rollerchain comprises two series of side bars or links 30 and 31. The links of each series are pivotally connected to one another by pins 32 which also form means for connecting each of the series of links in each strand and also for pivotally supporting ,rollers 33 which space the two series of links. The rollers 33 travel on track 34. The track 34, which, has a substantially horizontal section, an upwardly-inclined section, a downwardly-inclined section, and a second substantially horizontal section, corresponding to the described conveyor sections, supports the conveyor-screen between the sprocket wheels 14, 20 and 15 respectively. It will be observed that the inside pieces or links 30 of each strand of rollerchain also form the side pieces of the pans 29.-; The bottoms 35 of the pans 29 are secured to the side pieces 30, which also form one side of the roller chains, by angle brackets 36 riveted or otherwise connected to the sides and hottoms of the pans. It has previously been explained that when the conveyor-screen advances or travels up over the hump or knuckle and down again a certain amount of sliding of the coal being carried on the conveyor-screen will take place. I have provided a specially constructed pan bottom in order that free-runningv or uncontrolled sliding of coal on the inclines of the hump will be guarded against,but which will allow the regulated or retarded sliding of the coal so desirable -to obtain complete screening and separation of fines from.

lumps. The bottom piece 35 of each pan comprises a portion 37, forming the bottom of the pan, which has a downwardly depending end portion or flange 38 which is bent substantially at right angles to portion 37. The portions 37 of the pan bottoms are provided with screening apertures or slots 39 which extend slightly past the bend into the bent portion or flange 38 as shown at 39 The pan bottoms are so secured to the side pieces forming a part of the chains that when the strands of chain are in a horizontal position, the larger portion 37 will have a comparatively gradual upward incline or slope and the angular bent end portion 38 will have a short, steep clownward incline, almost vertical. When a series of pans are connected together, assuming the strands of chain to be horizontal,

a conveying and screening surface is formed.

tasse Q dined p -3 Qnn etee by the excesssive steep, oppositelyinelined, "almost vertical portions 38. The: conveying and screening surface so formed is substantially zig-zag in longitudinal contour. The gradually inclinedportions 37 support and'c'arry the material while" the portions '38 form shoulders or ab utment's tolprevent undue sliding of the material especi-allyon the inclines of the hump and ensure it-being carried along. i that a screeningand conveying surface is formed which will preventfree running. or uncontrolled sliding of coal on the inclines of the hump, but permit" regulated or retarded sliding of the coal. On the upward.

incline the shoulders 38 of the pans 29 support the coal and prevent free-running thereof, yet at the same time they permit some of the coal to slide over the inclined screen bottoms 37. The screening perforations or slots 39 in the screening bottoms 37 extend over the bends and into a part of shoulders or abutment s 38 so'that as the coal slides over the abut-ments the fines may more readily be separated. on the downward incline the portions 37 form a series of comparatively gradually sloped stepped inclines sloping downwardin the same general direction as the conveyor-screen, but

more gently. This allows a further retarded sliding and screeningof the coal;

'1 have provided means for receiving the fines separated from the lumps. together with means for advancing the fines to a designated point of discharge. I Fines sifting through the conveying and screening surface are caught in a trough 40 which is supported immediately under the -whole' length of the coal-carrying part of'the c-.on-' veyor-screen. Means are provided for ad-. vancing the screened material orfines received by the conveyor-trough LO and carry-' ing such material to a point of. discharge. In this instance, pushers or scrapers 41 depending from the conveyor-screeninto said trough serve this purpose. Any desired" number of scrapers 'or pushers may be carried onthe underside of the conveyor-screen at suitable distances apart. Inthe appara-. tus illustrated, each pusher or scraper; is an,

integralpart of a pan 29. The bottom 35 of the pan 29 is, in reality, of invertedthrough-shape', made of a slnglepiece of stamped metal. the portions 37' and; 38 going to make up the conveying and screening surface; the depending portion/l1 forming the scraper or fpusherworking in conveyortrough 40. As has already been explained,

the conveyorrtro u gh extends under the whole length of the coa l carr-yingsurface of the conveyor-screen and the sifted material' isadvancedr'along the conveyor-trough bv the depending pushersor scrapers 451.

v However, as the; fines have-been largely It. will be seen thereforecomprising,

separated om the la ps a th junc o of he loir va i l n nd h horizo tal portion 26', opening 2 is provided at this punt the ot om o he trough ea in intoa transverse screw conveyor 43 connect ing with the chute 44, by which the fines may becond uctedto a railway car, bin or other} wise-"disposedyofk The opening 42 in the bottom of the conveyor-trough is provided with a sliding gate 45 operated by wheel 46 so that if desired only a part of the fines may be disposed of here or the gate may be entirely closed and all the fines carried onto the f tscrew-conveyorl 47 chute L8. I

"The operation of the apparatus is'sufiiciently clear from the foregoing description and will nottherefore be'repeatedr It is emptying into sufficient to point out that as the runof the the fine coal along in the trough below. "It

will be observed that at-no time is thecoal subjected to undesirable shaking or rough agitation tending to break up "the lumps and form-additional quantities of fines; this being adequately. prevented notwithstanding the fact that the fines are completely sepa@ rated from the lumps by apparatus which takes up little," if any, more space than is required for the usual type of endlessconveyorialone." It is obviousfthat various changes can be made-in the details/of the apparatus without departing f r om the broad invention dis;

claims,

1'. Conveyingj'and' screening apparatus comprising," means providing a, I traveling conveying and screening surface inclined upwardly. and thengdownwardly between a point of feed and a point of discharge, whereby material carried by said surface will be agitated anda conveyor trough for Jun closed tsun mi set forth in the annexed screened material under 'sai d' conveyor and' screening surface andeXtending through out the; areagof upwa-rd and downward inclination (itaid surface.

2; Conveying and screening apparatus conveying" and screening surface inclined;

upwardly and then, downwardly to a degree 1 great-er than the angle of repose; of the material-upon aplane surface between-a,

means "providing a traveling.-

point of 'feed'and'a point of discharge, and t having. provision for retarding free-rung ning of 'm'aterial'on the inclines;

cal

conveyor-trough to advance screened ma terial along said conveyor-trough.

a. Conveying and screening apparatus comprising, means providing a traveling conveying, and screening surface inclined upwardly and then downwardly to a degree greater than the angle of repose of the material upon a plane surface between a point of feed and a point of discharge, said conveying and screening surface being provided with shoulders or abutments to retard free-running of material carried by said conveying and screening surface. v

5. Conveying and screening apparatus comprising, means providing a traveling conveying and screening surface inclined upwardly and then downwardlv between a point of feed and a point of discharge, said surface comprising a plurality of connected sections inclined with respect to the direc tion of travel of the conveying and screen-- ing surface, each of said sections being provided with an abutment or shoulder portion.

6. Conveying and screening apparatus comprising, in combination, means providing a traveling conveying and screening surface inclined upwardly and then downwardly between a point of feed and a pointy of discharge, said means comprising a plurality of connected sections each having a conveying and screening surface inclined with respect to the general direction --of travel of the conveying and screeningsurface as a whole, each of said sections being provided with an abutment or shoulder portion, a conveyor-trough supported under said conveying and screening surface, and means traveling with said conveying and screening surface for advancing material along said conveyor-trough.

7. Conveying and screening apparatus comprising, a conveyor inclined upwardly and then downwardly between a point of feed and a point of discharge, said conveyor comprising an endless series of connected pans, each of said pans having an apertured bottom inclined with respect to the direction of travel of said conveyor and assuming difi'ering positions with respect to the horizontal in the travel of said conveyor through its said upward and downward in clinations.

8. Conveying and screening apparatus comprising, a conveyor inclined upwardly and then downwardly between a point of feed and a point of discharge, said conveyor comprising an endless series of connected pans, each of saidpans having a bottom provided with screening apertures and inclined with respect to the direction of travel of said conveyor, said bottom having a depending abutment or shoulder portion extending toward the bottom of the next succeeding pan in the series. I

9. Conveying and screening apparatus comprising, a onveyor inclined upwardly and then downwardly between a point of feed and a point of discharge, said conveyor comprising an endless series of connected pans, each pan having a screening bottom inclined with respect to the direction of travel of said conveyor, said bottom having a depending abutment or shoulder portion extending toward the bottom of the next pan in the series and an integral depending pusher or scraper, in combination with a conveyor-trough supported under said conveyor in which said pushers or scrapers are adapted to work. I

1.0. Conveying and screening apparatus comprising a conveyor inclined upwardly and then downwardly. between a point of feed and a point of discharge, said conveyor comprising an endless series of connected pans, each pan having a bottom inclined with respect to the direction of travel of said conveyor, said bottom having a depending abutment or shoulder portion adapted to extend toward the bottom of the next pan when the pans are connected, the bottom of each pan being provided with slots or apertures which extend into part of the depending abutment or shoulder portion, in combination with a conveyor-trough supported under said conveyor, and means carried by the conveyor for advancing material along said conveyor-trough.

11. Conveying and screening apparatus comprising an endlessseries of connected pans forming a conveyor, each of said pans having a bottom provided with direction of travel of said conveyor and assuming differing positions with respect to the horizontal in the travel of said conveyor through its said upward and downward inclinations.

12. Conveying and screening apparatus comprising an endless series of connected pans forming a conveyor, each of said pans having a screening bottom inclined with respect to the direction of travel of said conveyor, said bottom having a depending abut- V screening apertures and inclined with respect to the ment or shoulder portion extending toward the bottom of the next pan in the series.

13. Conveying and screening apparatus comprising an endless series of connected pans forming a conveyor, each of said pans having an apertured bottom inclined with respect to the direction of travel of said conveyor, in combination with a conveyor trough supported under said conveyor and means carried by said conveyor for advancing material in said conveyor-trough in the direction of travel of said conveyor.

14. Conveying and screening apparatus comprising an endless series of connected pans forming a conveyor, each of said pans having an apertured bottom inclined with respect to the direction of travel of said conveyor, said bottom having a depending abutment or shoulder portion extending toward the bottom of the next pan in the series, in combination with a conveyor-trough and means carried by said conveyor to advance material in said conveyor-trough.

15. Conveying and screening apparatus comprising an endless series of connected pans forming a conveyor, each of said pans having a screening bottom inclined with respect to the direction of travel of said conveyor, said bottom having a depending abutment or shoulder portion extending toward the bottom of the next pan in the series and an integral depending pusher or scraper, in combination with a conveyor-trough supported under said conveyor in which said pushers or scrapers are adapted to work.

16, Conveying and screening apparatus comprising in combination, a conveyor embodying two endless strands ofroller chain, a track on which said roller chains are adapted to travel, a series of pans connected charge, a conveyor-trough supported under said conveyor and means carried by said conveyor for advancing material along said conveyor-trough. Y

17. In conveying and screening apparatus, a conveyor element comprising side to and carried by said strands of roller 1 pieces and an apertured bottom piece secured I to said side pieces in an inclined position relative to said side pieces, said bottom piece having a depending portion adapted to extend toward the bottom of the next succeeding element when the elements are connected in series. v

18. In conveying and screeningapparatus, a conveyor element comprising substantially parallel side pieces and a bottom piece connected to said side pieces and inclined in relation thereto, said bottom piece having a,

depending pusher portion and a depending shoulder portion, the bottom piece having screening apertures which extend into part of the shoulder portion.

In testimony whereof I hereunto aflix my signature.

EUGENE E. LANDAI-IL. 

